High-Quality Bridge Packers for Glazing and Window Installations

Black HIPS bridge packers for supporting and levelling sealed glass units during window and door installation. Available in widths from 15mm to 32mm, 5mm height, 100mm length. Sold in bags of 100.

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20mm Bridge Packers 24mm Bridge Packers 26mm Bridge Packers 32mm Bridge Packers

What are bridge packers?

Bridge packers (also called setting blocks or glazing bridges) are raised plastic supports placed at the bottom of a window or door frame before the sealed glass unit is inserted. Their bridge shape creates a gap between the glass and the frame sill, allowing water drainage and preventing the glass from resting directly on the frame. They are used in virtually every uPVC, aluminium and timber window installation in the UK. GSD stocks black HIPS bridge packers in widths from 15mm to 32mm with a fixed 5mm height and 100mm length, sold in bags of 100.

How to choose the right bridge packer

Match the bridge packer width to your sealed glass unit thickness. For standard double glazing (typically 24mm or 28mm units), use 24mm or 26mm bridge packers. For triple glazing (typically 36mm+ units), use 32mm bridge packers. Position minimum 2 per unit — one at each bottom corner, approximately 50mm in from the edge. For windows wider than 1200mm, add a third at the centre. Use flat glazing packers (not bridge packers) for toe-and-heel packing on the sides.
Trade Tip

Always check that bridge packers are not blocking the weep holes in the frame sill. Position them between drainage slots, not over them.

Frequently Asked Questions

What is the difference between bridge packers and flat packers?

Bridge packers have a raised profile that lifts the glass off the frame sill, allowing water drainage underneath. Flat packers are rectangular shims used on all edges for levelling. Most installations use both: bridge packers on the bottom for weight support and drainage, flat packers on the sides for toe-and-heel adjustment.

How many bridge packers per window?

Minimum 2 per glass unit — one at each bottom corner, set approximately 50mm in from the edge. For windows wider than 1200mm or for heavy triple-glazed units, add a third bridge packer at the centre of the bottom edge.

What width bridge packer do I need?

Match the width to your sealed glass unit thickness, not the frame rebate. For standard double glazing use 22mm-26mm. For triple glazing use 32mm. When in doubt, measure the glass unit itself.

Can I use flat packers instead of bridge packers on the bottom?

No — flat packers should not replace bridge packers at the bottom of the glass unit. Bridge packers are designed with a raised profile to allow water drainage. Using flat packers on the bottom blocks drainage and can cause water pooling, seal degradation and condensation.